Method of making excelsior



W. E. HUBBARD METHOD OF MAKING EXGELSIOR May 11, 1965 2 Sheets-Sheet 1 Filed Jun 24, 1 963 III] y 5 w. E. HUBBARD 3,182,696

METHOD OF MAKING EXCELSIOR Filed June 24, 1963 2 Sheets-Sheet 2 htat es Patent Ofiice 3,182,696. PatentedMz-ry 11,1965

This invention relates to a method of cutting excelsior strands to produce more desirable and more uniform strands.

Excelsior strands which are preferably of aspen wood have long been made by using a reciprocating knife to remove shavings from a block of wood. The cut is made by the knife on a surface of the wood that is generally parallel to its grain. In order to form the narrow strands a series of lancets or spurs are used ahead of the knife to score the wood slightly deeper than the thickness of the shaving that is removed by the knife, so that this shaving will fall apart int-o a number of individual narrow strands making up the excelsior. excelsior is controlled-by the spacing of the spur points and the thickness is controlled by the depth of cut of the knife.

In another basic method of cutting excelsior strands the spurs are eliminated and replaced by a splitter which resembles a comb with precision ground short teeth. This splitter is clamped on the top of the knife so that in this method the knife cuts the shaving from the wood and it is simultaneously split into the individual excelsior strands. j

Neither of these methods is desirably successful. Thus, where the spurs are used they must be individually sharpened frequently and aligned by hand which requires considerable labor. This is particularly true where the excelsior strand is narrow so that a large number ofspurs are required. Furthermore, the hand sharpening and aligning cannot be done with a desired uniform precision, so that it is practically impossible to produce uniform width strands. In addition, the spurs must be set to penetrate much deeper than the thickness of the desired strand that is shaved from the block by the knife. Often this excessive depth of the spurs is twice the desired thickness of the strand. This, of course, results in double cutting, as one pass of the spurs and knife causes the spurs to score to an excessive depth and then the repeating pass of the spurs and knife causes another cut. This double cutting tends to produce short, narrow and abraded excelsior strands. In addition, in cutting narrow strands it is necessary to use considerable force to push the wood between the spurs and this compresses and abrades the wood producing fine particles and dust. It also requires large amounts of power, thus raising the cost.

A major difficulty with the spur plus knife method of cutting excelsior is the tendency of the knife to dig into the wood deeper than the scoring indentations of the spurs This is particularly true of wood that is not prefectly straight grained. This excessive digging of the knife into the wood produces chips which may range from small strips to large splinters and are in the form of flat dug-out curls.

The width of the dividing of the shaving into individual strands is done by forcing the wood into the teeth of the splitter, this forces the wood into the roots of the teeth of the combed splitter so that the strands are compressed at the sides to such a degree that they emerge from the excelsior machine tightly curled on one end of each strand. These small, tight and strong clock spring curls tend to interlock with other strands, so that it is extremely diflicult to pull bale.

excelsior apart once it has been compressed and the strands have become firmly knitted together by the end In addition, by this method there is a limit to the narrowness of the strands because of the number of teeth par inch increases to make narrower and narrower strands, the depth of the individual tooth decreases con siderably so that the tendency to curl is greatly increased in these narrower strands. This also causes the knife to choke up so that the shutdowns of the machinery are frequent. In addition, the extreme pressure of the Wood against the splitter teeth to divide the shaving into strands seriously abrades the wood and produces a fine dust that is objectionable when the excelsior is usedfor bulk packaging. The high compression to which the strands are subjected by this method also causes the strands to be stiff and rough feeling.

The present invention eliminates the objectionable features of both the above methods, that is, the scoring spurs and knife method and the knife and splitter comb method.

In the method of this invention the wood is first scored at a surface that is substantially parallel to the grain of the wood in a plurality of closely spaced substantially parallel linear indentations with the distance between adjacent indentations determining the width of wood strips that are later cut from this surface. The block of wood at this surface is then cut at a depth to include these indentations to remove the strips from the block with these strips of course being as wide as the spacing-between the indentations. Shortly thereafter the strips are then split longitudinally into a plurality of excelsior strands.

In the preferred method. the cutting. and splitting are done substantially simultaneously. However, the method,

of this invention may also be practiced by cutting the strips from the wood prior to the splitting.

. In a preferred method the scoring of the wood substantially simultaneously compresses the wood laterally between the indentations to set up stresses in the wood strips of wood that are not cut into strands because the knife dug beneath the bottom of the identations scored by the spurs. Excelsior containing such chips cannot be used for many purposes.

The second method described above of cutting excelsior in which the spurs are eliminated and the shaving of wood removed by the knife is split by the combed splitter also raises many difficulties. Thus, this method sometimes produces a shaving which has been merely scored by the splitter and not split into the individual excelsior strands. This is not as serious as a chip produced by the other method but is also undesirable. Because the and case harden it at the indentation surfaces. Then, when the wood strips are split into strands the wood of each strand is distorted laterally toward the previous indenration which is thus toward the case hardened surface. This lateral displacement of the wood during the splitting avoids setting up additional stresses which would normally result from the splitting.

In this method a superior strand of excelsior is produced. Furthermore, these strands can. be very narrow and will be quite uniform in Width. This method also greatly reduces lateral compression of the wood as now the wood is scored into much wider strips than the previous method because these strips are later split into excelsior strands. As a result the excelsior strands are softer and more uniform. Becausethe pressure on the scoring spurs is lessened theproduction of dust and dirt are greatly reduced. a The scoring device does not excessively compress the Wood laterally because the individual scoring spurs are spaced apart to a much greater degree. The later splittering does not further compress the wood to a very marked degree as during the splitting the wood is merely forced back in the opposite direction toward the former scored indentations which, of course, are the lateral sides of the strips.

A major advantage of this method is that it eliminates substantially entirely the formation of the above described undesirable chips. Furthermore, because the lateral pressure on the wood is much less, there is less case hardening of anylsurface so that the strands are softer, more resilient and show less fiber damage so as to reduce the amount of dust and dirt produced. Also, thedouble cutting by the spurs as previously described is eliminated. This means that the excelsior strands can be longer and more uniform. In addition, because the lateral compressive forces on the strands are much reduced, there is practically no end curling of the strands that was formerly produced as described above.

An apparatus for practicing the method of this invention is shown in the accompanying drawings. Of the drawings: 7

FIGURE 1 is a plan view of an apparatus for practicing the method of this invention with this view being partially in section.

FIGURE 2 is a side elevational view of the apparatus of FIGURE 1.

FIGURE 3 is a sectional view taken substantially along line 33 of FIGURE 1.

FIGURE 4 is an enlarged fragmentary detail view of the apparatus of FIGURE 3..

' FIGURE 5 is a fragmentary sectional view taken substantially along line 5--5 of FIGURE 2.

FIGURE 6 is a fragmentary side elevational view of one side of a spur bar for scoring the wood.

FIGURE 7 is a view similar to FIGURE 6 but of the opposite side of this spur bar.

FIGURE 8 is a semi-diagrammatic view illustrating the series of operations involved in the method of mak ing excelsior.

, The excelsior is produced by cutting strands from one surface 10 of a block 11 of wood, preferably aspen. This surface is generally parallel to the grain of the wood.

The apparatus shown in the accompanying drawings comprises a frame 12 of steel or the like having an upwardly extending front part 13 and a sloped rear part 14. The designation of front and rear is taken with respect to the direction of normal travel of the apparatus in cutting excelsior strands from the wood.

The front part 13 has a hollow interior 15 open at the bottom, as indicated at 16, and communicating with this interior is a vertical top adjusting bolt 17 and a front .set screw 18 located adjacent the bottom of the front part 13.

Positioned within the hollow interior 15 isa spur bar 19 assembled with a spacer blank 20. This assembly is clasped between a shuttle L-bar 21 and a shuttle plate 22. The set screw 18, as shown in FIGURE 3, holds this assembly while the adjusting bolt 17 permits adjustment of the position of the assembly relative to the frame 12.

As shown most clearly in FIGURES 6 and 7, the spur bar 19 is provided on its rear face 23 with horizontal serrations 24. These serrations are very close together and are used for adjustment purposes. The opposite side of the bar 19, as shown in FIGURE 7, is provided with corresponding vertical serrations 25. The lower end of the bar is provided with scoring teeth 26 which may be spaced as desired to produce the desired width of excelsior strands. Thus, in various embodiments there may be 10, 12 or 14 teeth per inch, although greater or lesser numbers may be used as desired.

The horizontal serrations engage similar serrations in the L-bar 21 to hold the spur bar in adjusted position relative to the Wood 11. The spacer blank has serrations on one side similar to the serrations 25. On the other side it has horizontal serrations which engage similar serrations in the shuttle plate 22.

The sloped rear part 14 of the frame 12 is provided with a pair of clamping screws 27 which bear against a hold-down plate 28. The hold-down plate 28 holds an assembly of a cutting knife 29 and a splitter plate 30 on the downwardly and forwardly inclined surface 31 of the sloped rear part 14 of the frame. The splitter plate 30 and knife 29 have their lower edges extending through an opening 32 in the frame 12 to engage the wood 11. The lower end of the splitter 30 is provided with a series of teeth 33.

In the assembly the knife 29 and plate 30 are adjusted in rleative position to cut and split wood strips into excelsior strands of the desired thickness. The spur bar 19 in its assembly is adjusted vertically by the bolt 17 and set by the two set screws 18. The lateral position of the spur bar assembly is adjusted by means of the side set screws 34.

In operation the teeth 26 of the .spur bar 19 score the wood 11, as previously described, on forward movement of the assembly as indicated in FIGURE 8 at 35. This divides the wood into strips 36, Immediately behind the teeth 26, as shown in FIGURE 3, is the knife 29 to cut the strips from the block 11. As these strips pass on top of the knife 29 assembly they are engaged by the teeth 33 andare split as indicated at 37 into excelsior strands. The knife is diagrammatically illustrated at 38.

As can be seen, strips and strands of any width desired can be produced. Also, the width of the split can be determined by the number of teeth 33 in the splitter plate 30 and the spacing of these teeth relative to the teeth 26 of the spur bar 19.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the detail-s of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claim.

I claim:

The method of cutting excelsior strands of wood from a block of wood having a surface parallel to the grain of the wood, comprising: scoring the wood at said surface in a plurality of closely spaced, substantially parallel linear indentations with the distance between adjacent indentation-s determining the width of wood strips; substantially simultaneously compressing said wood laterally between said indentations to set up stresses and case harden the wood adjacent said indentations; cutting said block at a depth to include said indentations to remove the strips from the block; and splitting each of said strips longitudinally into a plurality of said strands subsequent to said scoring and laterally distorting each pair of strands on opposite sides of a said indentation toward each other substantially simultaneously with said splitting substantially to avoid setting up additional stresses as a result of said splitting.

References Cited by the Examiner UNITED STATES PATENTS 370,461 9/87 Fleck 144l86 1,020,100 3/12 Keogh 144186 2,739,627 3/56 Vohringer 241-28 WILLIAM W. DYER, 1a., Primary Examiner.

DONALD R. SCHRAN, Examiner. 

